In U.S. Pat. No. 6,822,123, a process was disclosed for the production of formaldehyde from methyl chloride. This process makes use of a catalytic reaction to oxidize methyl chloride with air to give formaldehyde and hydrogen chloride. the benefits of this scheme sere enumerated and included freeing the manufacture of formaldehyde from a dependence on methanol as a raw material.
Because merchant methyl bromide is considerably more expensive than methyl chloride, there would appear to be no advantage in substituting methyl bromide for methyl chloride in a process to manufacture formaldehyde. The drawback of using methyl bromide, however, disappears when byproduct hydrogen bromide is recycled to produce more methyl bromide. This result can be achieves by reacting hydrogen bromide with synthesis gas to form additional methyl bromide. Furthermore, in this recovery process, higher yields of methyl bromide can be obtained than achieved in the production of methyl chloride by the chlorination of methane.
Besides this advantage, other objects, features and benefits of the present invention will be recognized from the following description of the process.